Klaus Werner, Kareem El-Badry, Boris T. Gänsicke, Ken J. Shen
{"title":"Ultraviolet spectroscopy of the supernova Ia hypervelocity runaway white dwarf J0927−6335","authors":"Klaus Werner, Kareem El-Badry, Boris T. Gänsicke, Ken J. Shen","doi":"10.1051/0004-6361/202451635","DOIUrl":null,"url":null,"abstract":"The hot white dwarf (WD) J0927−6335 (Gaia DR3 5250394728194220800 with an effective temperature of <i>T<i/><sub>eff<sub/> = 60 000 K and a surface gravity of log<i>g<i/> = 7) was detected as the fastest known Galactic hypervelocity star with a space velocity of ≈2800 km s<sup>−1<sup/> and an atmosphere dominated by carbon and oxygen. It is thought to be the surviving WD donor predicted by the so-called dynamically driven double-degenerate double-detonation (D<sup>6<sup/>) type Ia supernova formation model. We analysed an ultraviolet spectrum of J0927−6335 that was recently obtained with the <i>Hubble<i/> Space Telescope and found very high abundances of iron and nickel. This might originate in the pollution of the remnant by the supernova Ia explosion, but it is uncertain to which extent atomic diffusion altered the chemical composition of the accreted material.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":null,"pages":null},"PeriodicalIF":5.4000,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Astronomy & Astrophysics","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1051/0004-6361/202451635","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
The hot white dwarf (WD) J0927−6335 (Gaia DR3 5250394728194220800 with an effective temperature of Teff = 60 000 K and a surface gravity of logg = 7) was detected as the fastest known Galactic hypervelocity star with a space velocity of ≈2800 km s−1 and an atmosphere dominated by carbon and oxygen. It is thought to be the surviving WD donor predicted by the so-called dynamically driven double-degenerate double-detonation (D6) type Ia supernova formation model. We analysed an ultraviolet spectrum of J0927−6335 that was recently obtained with the Hubble Space Telescope and found very high abundances of iron and nickel. This might originate in the pollution of the remnant by the supernova Ia explosion, but it is uncertain to which extent atomic diffusion altered the chemical composition of the accreted material.
期刊介绍:
Astronomy & Astrophysics is an international Journal that publishes papers on all aspects of astronomy and astrophysics (theoretical, observational, and instrumental) independently of the techniques used to obtain the results.